This case study presents the structured and evidence-informed approach toward developing a psychological assessment instrument within a national basketball federation. To this end, a two-phase approach was adopted. During the first phase, a focus group with the coaches was conducted to determine the key psychological characteristics pertinent to the case environment. This resulted in 10 identified key psychological characteristics. During the second phase, the results from the focus group were used to develop and conduct preliminary testing of a context-specific assessment instrument. Preliminary testing resulted in a refined instrument including nine characteristics. Based on the findings of this case study, the authors conclude this paper by outlining a number of reflections that can provide important considerations for sport psychologists, coaches, and talent identification and development organizations looking to develop and implement psychological assessment within their programs.